Electronic apparatus and method of cooling the electronic apparatus

ABSTRACT

An electronic apparatus includes a housing, a first heat-generating member provided in the housing, a heat-radiating member thermally connected to the first heat-generating member, a first fan module guiding air to the heat-radiating member, a second heat-generating member provided in the housing, a second fan module discharging air out of the housing, and a wall section provided in the housing, located between the first fan module and the second fan module.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based upon and claims the benefit of priorityfrom the prior Japanese Patent Application No. 2003-032448, filed Feb.10, 2003, the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to a electronic apparatus and amethod of cooling the electronic apparatus, which are particularlyfavorable for a notebook personal computer and the like.

[0004] 2. Description of the Related Art

[0005] A notebook personal computer comprises a housing in which acooling fan module is provided. The cooling fan module cools the entiresystem of the computer including a CPU. The compute also comprises atemperature sensing IC for sensing the temperature of the CPU. When thetemperature of the CPU exceeds a preset temperature, the IC supplies asensing signal to the cooling fan to rotate the cooling fan and thuscool the entire system of the computer including the CPU.

[0006] Jpn. Pat. Appln. KOKAI Publication No. 10-307648 discloses amethod of controlling the rotation speed of a single fan module based oninformation obtained from temperature sensors located in differentpositions as well as a position corresponding to a CPU in a notebookpersonal computer.

[0007] In the computer of the Publication, the temperature sensors havetheir own temperature values in advance. When the temperature actuallysensed by at least one temperature sensor is not lower than the presettemperature value, the fan module rotates to cool the entire system ofthe personal computer including the CPU.

[0008] Another system including a plurality of cooling fan modules toincrease the volume of cooled air and the number of main cooling pointsis proposed. This system is similar to the control method of the abovePublication in that the cooling fan modules turn on/off together.

[0009] As described above, conventionally, the entire system of apersonal computer including a CPU is cooled by turning on/off coolingfan modules or controlling the rotation speed of the cooling fanmodules.

[0010] Assume that a heating member such as a CPU that operates at highspeed and generates a large amount of heat is loaded into a notebookpersonal computer whose cooling space is limited. It is very likely thatthe cooling fan modules will have to rotate at all times. This is notrealistic in view of power consumption and noise.

BRIEF SUMMARY OF THE INVENTION

[0011] An object of the present invention is to provide a electronicapparatus that can efficiently cope with the thermal load of the system,and a method of cooling the electronic apparatus at a considerably smallamount of power consumption even though a heating member such as a CPUhaving a large heating value is located in restricted space.

[0012] An electronic apparatus according to an aspect of the presentinvention, comprises a housing, a first heat-generating member providedin the housing, a heat-radiating member thermally connected to the firstheat-generating member, a first fan module guiding air to theheat-radiating member, a second heat-generating member provided in thehousing, a second fan module discharging air out of the housing, and awall section provided in the housing, located between the first fanmodule and the second fan module.

[0013] Additional objects and advantages of the invention will be setforth in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the invention. Theobjects and advantages of the invention may be realized and obtained bymeans of the instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0014] The accompanying drawings, which are incorporated in andconstitute a part of the specification, illustrate embodiments of theinvention, and together with the general description given above and thedetailed description of the embodiments given below, serve to explainthe principles of the invention.

[0015]FIG. 1 is a perspective view illustrating a cooling fan module anda cooling passage on the bottom of a notebook personal computeraccording to an embodiment of the present invention.

[0016]FIG. 2 is a perspective view showing a mounting state of a systemcooling fan module of the personal computer according to the embodimentof the present invention.

[0017]FIG. 3 shows a relationship between a substrate and first andsecond mounting areas of the personal computer according to theembodiment of the present invention.

[0018]FIG. 4 is a sectional view showing a structure of a main bodyhousing of the personal computer, taken along line A-A OF FIG. 1.

[0019]FIG. 5 is a sectional view showing a structure of a main bodyhousing of the personal computer, taken along line B-B of FIG. 1.

[0020]FIG. 6 is a block diagram of the arrangement of a cooling controlcircuit of a system of the personal computer according to the embodimentof the present invention.

[0021]FIG. 7 shows contents of fan control registers held by an embeddedcontroller of the personal computer according to the embodiment of thepresent invention.

[0022]FIG. 8 shows contents of fan control tables set by the embeddedcontroller of the personal computer according to the embodiment of thepresent invention.

[0023]FIG. 9 shows contents of a control table required by BIOS of thepersonal computer according to the embodiment of the present invention.

[0024]FIGS. 10A and 10B are graphs each showing a relationship betweenthe temperature range of the control table shown in FIG. 9 and therotation speed of each fun module.

[0025]FIG. 11 is a flowchart of controlled contents of the CPU coolingfan module of the personal computer according to the embodiment of thepresent invention.

[0026]FIG. 12 is a flowchart of controlled contents of the systemcooling fan module according to the embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0027] A notebook personal computer according to an embodiment of thepresent invention will now be described with reference to theaccompanying drawings.

[0028]FIG. 1 shows the bottom of a main body housing 20 of a personalcomputer (PC) when it is viewed from the back thereof. In FIG. 1,reference numeral 21 indicates a heat sink that is thermally connectedto a CPU 30 located on the underside of the housing 20 to diffuse andcool the heat generated from the CPU 30. The heat sink 21 is provided ina CPU first cooling passage together with a CPU cooling fan module 23.The first cooling passage is spatially separated from, e.g., othercircuit elements of the personal computer by a partition wall 22.

[0029] A fan panel 24 and a CPU panel (not shown) are mounted on thebottom of the main body housing 20 to cover a first opening O1.Actually, the first opening O1 includes the CPU 30, heat sink 21 and CPUcooling fan module 23.

[0030] The fan panel 24 has a slit serving as a second opening O2through which cooled air is introduced by rotation of the CPU coolingfan module 23.

[0031] The cooling fan module 23 is secured to the cooling passage withscrews 25 and the fan panel 24 and CPU panel are mounted with screws 26or the like. When the cooling fan module 23 rotates under theseconditions, outside air, which is taken from above the fan panel 24, isblown toward the heat sink 21. The air is then guided outside the mainbody housing 20 through a fourth opening 04 formed on the back of thehousing 20.

[0032] When the above personal computer is actually used, a slight spaceis secured between the bottom of the personal computer and the mountingsurface such as the top of a desk by legs F formed on the bottom of themain body housing 20 (FIG. 1 shows only two legs on the back of thehousing but the housing requires at least four legs). This space allowsair to be inhaled through the bottom of the housing 20.

[0033] The heat generated from the CPU 30 moves to the heat sink 21 andthe flow of air discharged from the fan 23 cools the heat sink 21. TheCPU 30 is cooled accordingly.

[0034] Reference numeral 28 (broken line) denotes a system cooling fanmodule. The system control fan module 28 cools circuit elementsexcluding the CPU 30 and heat sink 21 at once in the main body housing20.

[0035] The system cooling fan module 28 is provided at the exit of aU-shaped second cooling passage that is formed to detour around theabove CPU first cooling passage formed by the partition wall 22. Thecircuit elements other than the CPU 30 are arranged appropriately in thesecond cooling passage.

[0036] According to the present embodiment, the amount of air moved byone rotation of the CPU cooling fan module 23 is larger than that of airmoved by one rotation of the system cooling fan module 28. The CPUcooling fan module 23 has a larger cooling capacity.

[0037] Therefore, even though the thermal load of the CPU 30 is equal tothat of each of the circuit elements other than the CPU 30, the CPUcooling fan module 23 can cool the CPU 30 at a lower rotation speed.

[0038]FIG. 2 illustrates a mounting state of the system cooling fanmodule 28. The system cooling fan module 28 is mounted in a position ofthe main body housing 20, which corresponds to the second coolingpassage, by screws 29.

[0039] In FIG. 2, reference numeral 22 a denotes partition wall fittingsections that are formed integrally with the inner surface of the mainbody housing 20 and projected therefrom.

[0040] Since the partition wall fitting sections 22 a are fitted to thepartition wall 22, the first cooling passage for the CPU 30 and thesecond cooling passage for the circuit elements other than the CPU 30are spatially separated from each other. Thus, the CPU 30 and the othercircuit elements are cooled individually by the rotation of the CPUcooling fan module 23 and that of the system cooling fan module 28.

[0041]FIG. 3 shows mounting areas in a circuit board CB formed in themain body housing 20 of the personal computer. The mounting surface ofthe circuit board CB is divided into first and second mounting areas A1and A2 by the partition wall 22.

[0042] The first mounting area A1 includes the CPU 30, heat sink 21thermally connected to the CPU 30, and CPU cooling fan module 23.

[0043] The second mounting area A2 includes the system cooling fanmodule 23 and the circuit elements other than the CPU 30.

[0044] In the first mounting area A1, the CPU cooling fan module 23rotates to inhale air in the direction orthogonal to FIG. 3. The airdischarged above from the CPU cooling fan module 23 is heat-exchangedwith the heat sink 21 to cool the CPU 30. The heated air is dischargedoutside the main body housing 20 through the fourth opening 04 (notshown) from above the heat sink 21.

[0045] In the second mounting area A2, the air inhaled from the leftside of FIG. 3 by the rotation of the system cooling fan module 28 flowsin the form of the letter U so as to keep away from the first mountingarea A1 on the circuit board CB. While the air is flowing, it isheat-exchanged with the circuit elements to cool them. The cooled air isdischarged out of the main body housing 20 through the third opening O3(not shown) on the right side of FIG. 3 by the system cooling fan module28.

[0046]FIG. 4 shows a section of the main body housing 20 of the personalcomputer, taken along line A-A of FIG. 1. As in FIG. 1, the top of thesection corresponds to the bottom of the main body housing 20.

[0047] Like FIG. 1, FIG. 4 shows the main body housing 20 from which thefan panel 24 is detached. The heat sink 21 is thermally connected to theCPU 30 mounted on the circuit board CB to cover the CPU 30. The heatsink 21 is fixed to the circuit board CB. As shown in FIG. 3, too, thefirst mounting area A1 including the CPU 30 and heat sink 21 and thesecond mounting area A2 including the system cooling fan 28 arespatially separated from each other by the partition wall 22.

[0048]FIG. 5 shows a section of the main body housing 20 of the personalcomputer, taken along line B-B of FIG. 1. As in FIG. 1, the top of thesection corresponds to the bottom of the main body housing 20.

[0049] In the first mounting area A1, the air taken through the secondopening O2 of the fan panel 24 from above FIG. 5 by the rotation of theCPU cooling fan module 23 is heat-exchanged by the heat sink 21. Theheat sink 21 is projected from the right side of the CPU cooling fanmodule 23 and connected to the CPU 30. The heat-exchanged air is thendischarged out of the housing 20 through the fourth opening O4. The airflows in the form of the letter L.

[0050] The flow path of the first mounting area A1 is longer and its airresistance is lower than that of the flow path of the second mountingarea A2 having a number of bending portions.

[0051] Consequently, the CPU cooling fan module 23 can cool the CPU 30more efficiently than the system cooling fan module 28 since its airvolume is greater than that of the cooling fan module 28.

[0052]FIG. 6 shows a circuit arrangement for cooling the entire systemincluding the CPU cooling fan module 23 and system cooling fan module28. A temperature sensing IC 31 monitors the temperature of the CPU 30thermally connected to the heat sink 21, which is one to be controlled.

[0053] The temperature sensing IC 31 is connected to a south bridgecircuit 32 via a serial bus 33 and supplies a sensed-temperature signalTHRM# of the CPU 30 to the south bridge circuit 32 and embeddedcontroller 34.

[0054] When the temperature of the CPU 30 exceeds a preset temperature,the IC 31 senses it and sends a cooling-request signal FANREQ to theembedded controller 34.

[0055] The south bridge circuit 32 is connected to the CPU 30 to controlthe interface of the entire system. The south bridge circuit 32 is alsoconnected to a BIOS 35 and embedded controller 34.

[0056] The BIOS 35 is a program executed between the south bridgecircuit 32 and OS 36 to control various peripheral devices that make upthe personal computer.

[0057] On the other hand, the system cooling fan module 28 andtemperature sensing element 38 are provided at circuit elements 37 to becooled excluding the CPU 30.

[0058] The temperature sensing element 38 is formed of, e.g., athermistor. It is provided in that position of the circuit elements 37which greatly decreases in performance and thus needs to be cooledbecause of a temperature rise. The element 38 sends a sensing signalcorresponding to the sensed temperature to the embedded controller 34.

[0059] The embedded controller 34 holds a set value for individuallycontrolling the rotation speeds of the CPU cooling fan module 23 andsystem cooling fan module 28 which are provided by the BIOS 35 throughthe south bridge circuit 32.

[0060] Upon receiving the sensed-temperature signal THRM# andcooling-request signal FANREQ from the temperature sensing IC 31, theembedded controller 34 causes a fan driving circuit 39 to apply avoltage to the CPU cooling fan module 23 to rotate the fan module 23 inaccordance with the set value.

[0061] An operation of the personal computer according to theabove-described embodiment will now be described.

[0062]FIG. 7 shows the contents of a fan control register R held by theembedded controller 34. The contents of the register R can beread/written by the BIOS 35 through the south bridge circuit 32.

[0063] The fan control register R includes a CPU fan control register R1for the CPU cooling fan module 23 and a system fan control register R2for the system cooling fan module 28.

[0064] The CPU fan control register R1 includes a zeroth register. Thezeroth register holds rotation speed information of the CPU cooling fanmodule 23 required by the BIOS 35 or OS 36.

[0065] The system fan control register R2 includes zeroth to thirdregisters.

[0066] The zeroth register of the register R2 holds rotation speedinformation of the system cooling fan module 28 required by the BIOS 35or OS 36.

[0067] The first register of the register R2 holds temperatureinformation for shifting an operation of the system cooling fan module28 from off-state to on-state in response to a sensing signal from thetemperature sensing element 38.

[0068] The second register of the register R2 holds temperatureinformation for shifting an operation of the system cooling fan module28 from on-state to off-state in response to a sensing signal from thetemperature sensing element 38.

[0069] The third register of the register R2 holds rotation speedinformation of the system cooling fan module 28 required in response toa sensing signal from the temperature sensing element 38.

[0070] The zeroth register of the CPU fan control register R1 and thezeroth and third registers of the system fan control register R2 holdinformation of the rotation speeds required for the respective fans. Tostop the rotation, they hold a value “0”.

[0071]FIG. 8 shows contents of a fan control table T held by theembedded controller 34. The contents of the table T are set by theinternal processing of the embedded controller 34.

[0072] The fan control table T includes a CPU fan control internal tableTi for the CPU cooling fan module 23 and a system fan control internaltable T2 for the system cooling fan module 28.

[0073] The CPU fan control internal table T1 includes a zeroth table anda first table.

[0074] The rotation speed information of the CPU cooling fan module 23transmitted from the BIOS 35 or OS 36 is set in the zeroth table of thetable T1.

[0075] The rotation speed information obtained when the CPU cooling fanmodule 23 rotates in response to a cooling request signal FANREQ fromthe temperature sensing IC 31 is set in the first table of the table T1.

[0076] The system fan control internal table T2 includes zeroth tosecond tables.

[0077] The rotation speed information of the system cooling fan module28 transmitted from the BIOS 35 or OS 36 is set in the zeroth table ofthe table T2.

[0078] The rotation speed information obtained when the system coolingfan module 28 rotates in response to a cooling request signal FANREQfrom the temperature sensing IC 31 is set in the first table of thetable T2.

[0079] The rotation speed information obtained when the system coolingfan module 28 rotates in response to a sensing signal from thetemperature sensing element 38 is set in the second table of the tableT2.

[0080] Information of the rotation speeds necessary for the respectivefans is set in the zeroth and first tables of the CPU fan controlinternal table Ti and the zeroth to second tables of the system fancontrol internal table T2. To stop the rotation, a value “0” is set inthe tables.

[0081]FIG. 9 is a control table TB for the CPU cooling fan module 23 andsystem cooling fan module 28 that are managed by the BIOS 35. The BIOS35 reads the temperature of the CPU 30 sensed by the temperature sensingIC 31 from the south bridge circuit 32 via the serial bus and reads therotation speed information of each of the fan modules 23 and 28 from thecontrol table TB based on the sensed temperature. The read rotationspeed information is supplied to the embedded controller 34 and held inthe zeroth registers of the CPU fan control register R1 and system fancontrol register R2 of the fan control register R. The fan modules 23and 28 are therefore required to rotate.

[0082] In the control table TB, different rotation speeds are preset tothe CPU cooling fan module 23 and system cooling fan module 28 forrespective temperature ranges. In the lowest-temperature range 1, forexample, a value “0” is set to both the rotation speed A1 of the CPUcooling fan module 23 and the rotation speed B1 of the system coolingfan module 28. Consequently, the fan modules 23 and 28 can be preventedfrom uselessly rotating in a low-temperature range.

[0083] After that, different rotation speeds are preset to the CPUcooling fan module 23 and system cooling fan module 28 for eachtemperature range. The amount of air (cooling capacity) of the CPUcooling fan module 23 is larger than that of the system cooling fanmodule 28 as described above. Thus, the rotation speed An of the fanmodule 23 is set relatively lower than the rotation speed Bn of the fanmodule 28 even in the same temperature range n.

[0084] Assume that the rotation speed of the CPU cooling fan module 23increases linearly as the temperature of the temperature range rises asshown in FIG. 10A.

[0085] Assume that the system cooling fan module 28 rotates at a presetmaximum rotation speed even though the temperature of the temperaturerange rises and exceeds a certain value as shown in FIG. 10B.

[0086]FIG. 11 shows a process of rotation control of the CPU cooling fanmodule 23 executed by the embedded controller 34 based on the contentsthat have been described with reference to FIGS. 7 to 10B.

[0087] First, the controller 34 determines whether a request to controlthe CPU cooling fan module 23 is issued from the BIOS 35 (step A01).

[0088] Only when the controller 34 determines that the request isissued, it holds the rotation speed information of the fan module 23transmitted from the BIOS 35 in the zeroth register of the CPU fancontrol register R1 of the control register R, transfers the contents ofthe zeroth register to the zeroth table of the CPU fan control internaltable T1 of the fan control table T, and sets them to the zeroth table(step A02).

[0089] After that, the controller 34 determines whether the temperaturesensing IC 31 issues a cooling request signal FANREQ (step A03).

[0090] When the signal FANREQ is not issued, the controller 34 sets therotation speed “0” indicating that the fan module 23 does not rotate inthe first table of the CPU fan control internal table T1 (step A04).When the signal FANREQ is issued, the controller 34 sets a preset value,and more specifically, the maximum rotation speed of the fan module 23in the first table of the table T1 (step A05).

[0091] After that, the value “0” indicating that the CPU cooling fanmodule 23 does not rotate is temporarily set as a target rotation speedfor driving the fan module 23 (step A06).

[0092] A loop process is performed based on the total number of tablesof the CPU control internal table T1 of the fan control table T (stepsA07 to A10).

[0093] In the loop process, when the target rotation speed of the CPUcooling fan module 23 is not higher than the set value of the i-th tableindicated by the loop count value i, a process of resetting the setvalue as a target rotation speed is repeated while updating the loopcount value i by “+1” in sequence from “1” until the value i reaches themaximum (=2).

[0094] In the loop process, the target rotation speed is updated byselecting the largest one from the rotation speeds of the CPU coolingfan module 23 in each of the tables of the CPU fan control internaltable T1.

[0095] After the loop process, the CPU cooling fan module 23 rotates atthe target rotation speed (step A11). The control process of the CPUcooling fan module 23 ends.

[0096]FIG. 12 shows a process of rotation control of the system coolingfan module 28 executed by the embedded controller 34.

[0097] First, the controller 34 determines whether a request to controlthe system cooling fan module 28 is issued from the BIOS 35 (step B01).

[0098] Only when the controller 34 determines that the request isissued, it holds the rotation speed information of the fan module 28transmitted from the BIOS 35 in the zeroth register of the system fancontrol register R2 of the control register R, transfers the contents ofthe zeroth register to the zeroth table of the system fan controlinternal table T2 of the fan control table T, and sets them to thezeroth table (step B02).

[0099] After that, the controller 34 determines whether the temperaturesensing IC 31 issues a cooling request signal FANREQ (step B03).

[0100] When the signal FANREQ is not issued, the controller 34 sets therotation speed “0” indicating that the fan module 28 does not rotate inthe first table of the system fan control internal table T2 (step B04).

[0101] When the signal FANREQ is issued, the controller 34 sets a presetvalue and, more specifically, the maximum rotation speed of the fanmodule 28 in the first table of the table T2 (step B05).

[0102] The controller 34 then determines whether the temperature of thecooling passage sensed by the temperature sensing element 38 is notlower than the temperature held in the first register of the system fancontrol register R2 (step B06).

[0103] When the controller 34 determines that the temperature of thecooling passage is not lower than the temperature held in the firstregister, it sets the rotation speed information of the fan module 28,which is held in the third register of the register R2, in the secondtable of the table T2 (step B07).

[0104] When the controller 34 determines in step B06 that thetemperature sensed by the element 38 is lower than the temperature heldin the first register of the register R2, it determines whether thesensed temperature is lower than temperature held in the second registerof the register R2 (step B08).

[0105] Only when the controller 34 determines that the temperaturesensed by the element 38 is lower than the temperature held in thesecond register of the register R2, it sets the rotation speed “0”indicating that the fan module 28 does not rotate in the second table ofthe system fan control internal table T2 (step B09).

[0106] After that, the value “0” indicating that the system cooling fanmodule 28 does not rotate is temporarily set as a target rotation speedfor driving the fan module 28 (step B10).

[0107] A loop process is performed based on the total number of tablesof the system fan control internal table T2 of the fan control table T(steps B11 to B14).

[0108] In the loop process, when the target rotation speed of the systemcooling fan module 28 is not higher than the set value of the i-th tableindicated by the loop count value i, a process of resetting the setvalue as a target rotation speed is repeated while updating the loopcount value i by “+1” in sequence from “1” until the value i reaches themaximum (=3).

[0109] In the loop process, the target rotation speed is updated byselecting the largest one from the rotation speeds of the system coolingfan module 28 in each of the tables of the system fan control internaltable T2.

[0110] After the loop process, the system cooling fan module 28 rotatesat the target rotation speed (step B15). The control process of thesystem cooling fan module 28 ends.

[0111] As described above, the CPU 30 and the other circuit elementsconfiguring the system are spatially separated into two coolingpassages. The elements in the respective cooling passages areindividually cooled using the CPU cooling fan module 23 and systemcooling fan module 28. Consequently, though the CPU 30 having a largeheating value is loaded into a notebook personal computer, it can becooled with efficiency even at such a relatively low rotation speed asnot to cause any noise problem if the CPU cooling fan module 23 has ahigh volume of air to cope with the thermal load of the computer.

[0112] The circuit elements other than the CPU 30 are arranged in thecooling passage spatially separated from that of the CPU 30. Basically,the circuit elements are cooled by the rotation of the system coolingfan module 28 independently of the heat generation of the CPU 30.

[0113] The system of the CPU 30 and that of the circuit elements otherthan the CPU 30 are cooled separately from each other. The coolingoperation has only to be performed to a required extent in a requiredsystem. Wasted power consumption can thus be avoided.

[0114] When the step A03 in FIG. 11 determines that the cooling-requestsignal FANREQ is input to the embedded controller 34 from thetemperature sensing IC 31, a value preset in the first table of the CPUfan control internal table T1 and, more specifically, the maximumrotation speed of the CPU cooling fan module 23 is set in the subsequentstep A05. When the step B03 in FIG. 12 make the same determination, avalue preset in the first table of the table T2 and, more specifically,the maximum rotation speed of the system cooling fan module 28 is set inthe subsequent step B05.

[0115] When the heating value of the CPU 30 that is the operation centerof the personal computer is extraordinarily high, not only the CPUcooling fan module 23 for the CPU 30 but also the system cooling fanmodule 28 for the system other than the CPU 30 rotates at the maximumrotation speed and these fans cool the two cooling passages at thelargest cooling capacity.

[0116] Consequently, the cooling of the cooling passage on the systemother than the CPU 30 can contribute to that of the CPU 30.

[0117] As has been described with reference to FIGS. 7 to 9, 11 and 12,the BIOS 35 sets the rotation speed of each of the CPU and systemcooling fan modules 23 and 28 and a comparative value between thetemperatures sensed by the temperature sensing IC 31 and temperaturesensing element 38 in the embedded controller 34. Based on the contentsset in the BIOS 35, the controller 34 controls the rotation of the fanmodules 23 and 28.

[0118] The personal computer has its own temperature characteristicssuch as air-flowing efficiency of each of two cooling passages spatiallyseparated by the partition wall 22, an amount of air cooled by the fanmodules 23 and 28, and an amount of heat generated from the CPU 30 andthe other circuit elements. If the BIOS 35 sets proper contents in themain body housing 20 of the personal computer according to thetemperature characteristics, the CPU 30 and the other circuit elementscan reliably be cooled with high efficiency without wasting power.

[0119] As shown in FIG. 9 and FIGS. 10A and 10B in particular, the BIOS35 sets the rotation speed of each of the CPU and system cooling fanmodules 23 and 28 to a higher value in accordance with a rise in thetemperature of ranges including the temperatures sensed by thetemperature sensing IC 31 and temperature sensing element 38 rise.

[0120] Power consumption can thus be minimized without any wasteddriving of the fan modules 23 and 28 at a high rotation speed. The userof the personal computer can be provided with a comfortable environmentfor use.

[0121] In the foregoing embodiment, two spaces corresponding to thefirst and second mounting areas A1 and A2 on the circuit board CB areseparated from each other by the partition wall 22. However, thefollowing modification can be made, depending on the relationship inarrangement between the CPU 30 and heat sink 21 on the mounting area A1and some of the circuit elements on the mounting area A2 that have alarge heating value. The two spaces can be connected to each other byforming a notch in the partition wall 22 to inhale air corresponding tothe second mounting area A2 and discharge it from the fourth opening 04by rotating the CPU cooling fan module 23 or inhale air corresponding tothe first mounting area A1 and discharge it from the third opening 03 byrotating the system cooling fan module 28.

[0122] The notch formed in an appropriate position of the partition wall22 allows the two spaces to be connected to each other to mutuallyassist in the cooling operations of the fan modules 23 and 28. When onlyone of the fans is used to cool an element on one side, it can coolanother element on the other side to some extent. Consequently, thepersonal computer can be operated efficiently by reducing powerconsumption.

[0123] The forgoing embodiment is directed to a notebook personalcomputer. The present invention is not limited to the notebook personalcomputer but can be applied to an information processing apparatus, suchas a board type personal computer and a PDA (personal digitalassistant), if the apparatus has a processing performance and cools theheat generated from a circuit element with efficiency though the size ofthe housing is restricted.

[0124] Additional advantages and modifications will readily occur tothose skilled in the art. Therefore, the invention in its broaderaspects is not limited to the specific details and representativeembodiments shown and described herein. Accordingly, variousmodifications may be made without departing from the spirit or scope ofthe general inventive concept as defined by the appended claims andtheir equivalents.

What is claimed is:
 1. An electronic apparatus comprising: a housing; afirst heat-generating member provided in the housing; a heat-radiatingmember thermally connected to the first heat-generating member; a firstfan module guiding air to the heat-radiating member; a secondheat-generating member provided in the housing; a second fan moduledischarging air out of the housing; and a wall section provided in thehousing, located between the first fan module and the second fan module.2. The electronic apparatus according to claim 1, wherein theheat-radiating member is provided at an end of the housing, the firstfan module is provided in the housing more inwardly than theheat-radiating member, and the first fan module guides air outside thehousing by blowing air to the heat-radiating member.
 3. The electronicapparatus according to claim 2, wherein the second fan module isprovided at the end of the housing, and the second heat-generatingmember is provided in the housing more inwardly than the second fanmodule.
 4. An electronic apparatus comprising: a circuit board includinga first mounting area on which a heat-generating component is mountedand a second mounting area different from the first mounting area; ahousing including the circuit board and having a first opening opposedto the first mounting area; a heat-radiating member mounted on the firstmounting area and thermally connected to the heat-generating component;a first fan module mounted on the first mounting area to guide air tothe heat-radiating member; a partition wall which extends in a directionof the circuit board from the first opening, the partition wall beingformed integrally with the circuit board as one component; and a coverattached to the first opening to cover the first mounting area andhaving a second opening opposed to the first fan module.
 5. Theelectronic apparatus according to claim 4, further comprising: a thirdopening formed in the housing in correspondence with the second mountingarea; and a second fan mounted on the second mounting area to dischargeair from the housing through the third opening.
 6. The electronicapparatus according to claim 5, wherein the partition wall is locatedbetween the first fan module and the second fan module.
 7. Theelectronic apparatus according to claim 4, wherein the housing has afourth opening opposed to the heat-radiating member, and the first fanmodule inhales air from the housing through the second opening, blowsthe inhaled air on the heat-radiating member and discharges the airoutside the housing through the fourth opening.
 8. The electronicapparatus according to claim 7, wherein the first fan module has an airinhaling port opposed to the second opening and an air discharging portopposed to the heat-radiating member.
 9. The electronic apparatusaccording to claim 7, wherein the partition wall surrounds the firstmounting area except for a portion corresponding to the fourth opening.10. The electronic apparatus according to claim 4, wherein the partitionwall contacts the circuit board.
 11. The electronic apparatus accordingto claim 5, wherein the partition wall has a notch and the first fanmodule discharges air outside the first and second mounting areas fromthe third opening through the notch.
 12. The electronic apparatusaccording to claim 5, wherein the partition wall has a notch and thesecond fan module discharges air outside the first and second mountingareas through the notch.
 13. An electronic apparatus comprising: ahousing; a first heat-generating member provided in the housing; aheat-radiating member thermally connected to the first heat-generatingmember; a first fan module guiding air to the heat-radiating member; asecond heat-generating member provided in the housing separately fromthe first heat-generating member; a second fan module discharging airout of the housing; a wall section provided in the housing, locatedbetween the first fan module and the second fan module; firsttemperature sensing means for sensing a temperature of the firstheat-generating member; first rotation control means for controllingrotation of the first fan module in accordance with a sensing result ofthe first temperature sensing means; second temperature sensing meansfor sensing a temperature of an inside of the housing; and secondrotation control means for controlling rotation of the second fan modulein accordance with a sensing result of the second temperature sensingmeans.
 14. The electronic apparatus according to claim 13, wherein thefirst temperature sensing means senses that the temperature of the firstheat-generating member exceeds a given temperature and supplies asensing signal to both the first and second rotation control means, thefirst rotation control means rotates the first fan module at a maximumrotation speed in response to the sensing signal from the firsttemperature sensing means, and the second rotation control means rotatesthe second fan module at a maximum rotation speed in response to thesensing signal from the first temperature sensing means.
 15. Theelectronic apparatus according to claim 13, further comprising settingmeans for setting both a rotation speed of the first fan module and acomparative value of the temperature sensed by the first temperaturesensing means in the first rotation control means, and wherein the firstrotation control means controls rotation of the first fan module basedon contents set by the setting means.
 16. The electronic apparatusaccording to claim 13, further comprising setting means for setting botha rotation speed of the second fan module and a comparative value of thetemperature sensed by the second temperature sensing means in the secondrotation control means, and wherein the second rotation control meanscontrols rotation of the second fan module based on contents set by thesetting means.
 17. The electronic apparatus according to one of claims15 and 16, wherein the setting means sets the rotation speed of each ofthe first and second fan modules to a larger value in accordance with arise in temperature of a range including the temperature sensed by oneof the first and second temperature sensing means.
 18. A method ofcooling an electronic apparatus including a housing, a firstheat-generating member provided in the housing, a heat-radiating memberthermally connected to the first heat-generating member, a first fanmodule guiding air to the heat-radiating member, a secondheat-generating member provided in the housing separately from the firstheat-generating member, a second fan module discharging air out of thehousing, and a wall section provided in the housing, located between thefirst fan module and the second fan module, the method comprising: atemperature sensing step of sensing that the temperature of the firstheat-generating member exceeds a given temperature and outputting asensing signal; a first rotation control step of rotating the first fanmodule at a maximum rotation speed in response to the sensing signaloutput in the temperature sensing step; and a second rotation controlstep of rotating the second fan module at a maximum rotation speed inresponse to the sensing signal output in the temperature sensing step.19. A method of cooling an electronic apparatus including a housing, afirst heat-generating member provided in the housing, a heat-radiatingmember thermally connected to the first heat-generating member, a firstfan module guiding air to the heat-radiating member, a secondheat-generating member provided in the housing separately from the firstheat-generating member, a second fan module discharging air out of thehousing, and a wall section provided in the housing, located between thefirst fan module and the second fan module, the method comprising: atemperature sensing step of sensing a temperature of the firstheat-generating member; a setting step of setting both a rotation speedof the first fan module and a comparative value of the temperaturesensed in the temperature sensing step; and a rotation control step ofcontrolling rotation of the first fan module in accordance with contentsset in the setting step and the temperature of the first heat-generatingmember sensed in the sensing step.